Distributor for distributing cooling liquid



Jan. 7, 1969 I D. R. HOWARD 3,420,447

DISTRIBUTOR FOR DISTRIBUTING COOLING LIQUID Fileq May 2, 1966 Sheet of 2 INVEN'T'QR DAVID R. HOWARD HIS A'r'roaNEY D. R. HOWARD DISTRIBUTOR FOR DISTRIBUTING COOLING LIQUID Jan- 1, 1969 Filed May 2. 1966 Sheet v LY FIG. 3.

lNveN'roR DAVID R- HOWARD jl aflwt s A'rmanev United States Patent 6 Claims ABSTRACT OF THE DISCLGSURE The disclosure of this invention relates to a fluid cooling system of the type used to cool hot strip as it leaves the last stand of the finishing train. The disclosure includes a header into which a controllable supply of fluid is introduced. To the header there is connected a plurality of delivery pipes mounted so that they extend in a vertical direction with their lower ends above the strip which passes beneath the pipes. Within each pipe there is provided a series of streamlining sections. Each pipe, with respect to its upper ends, terminates in a chamber dis posed above the header in which the chamber communicates with the header through restricted passages.

This invention relates to cooling systems for cooling strip material, for example strip metal emerging from a stand of a rolling mill. It has previously been suggested to deliver cooling water or other liquid onto the horizontally moving strip in the form of low-velocity, unbroken jets, utilising syphon tubes connected to open tanks arranged above the strip path. With this arrangement, however, the rate of delivery of liquid from each tube can be adjusted only by adjustment of the level of water in the tank. Secondly, there is an inherent delay between turning on or turning olf the water supply to the tank and the initiation or cessation of liquid delivered by the tubes; this is because, during start up, the level of liquid in the tank must rise above the highest point of the syphon tubes before delivery starts and, for shut down, the syphon tubes must drain all the liquid from the tank above the level of the take otf points before delivery is cut off.

In our British complete specification No. 16983/65, there is described a cooling system comprising a closed header transversely disposed over the strip to be cooled and connected to a supply of cooling liquid, and a series of delivery pipes spaced along the header, each being connected to the header at or adjacent the top thereof and, after extending above the level of the header, terminating above the strip so as to deliver the cooling liquid onto the moving strip in an unbroken, low velocity, jet. In particular, each delivery pipe extends upwardly from the header in a circular arc and terminates in a straight downwardly extending part. Each pipe is connected through a restriction to the interior of the header, so that the flow through the pipes is equalised.

In the present invention, a cooling system comprises a header connected to a controllable supply of liquid coolant and a plurality of delivery pipes connected to or in the header, each such pipe communicating with the interior of the header via a restricted passage and having means for promoting streamline flow therewithin, prior to discharge from the pipe. The flow through the restriction gives rise to turbulence within the pipe; in order that the liquid reaching the moving strip should have laminar, or near laminar, flow the liquid leaving each discharge pipe should contain as little turbulence as possible and the means for promoting streamlined flow is designed to that end.

Because of the streamlining means, the pipe may be short relative to that required in the construction of British complete specification No. 16983/ 65. In particular, each pipe may be substantially straight and may be arranged substantially vertically, passing through the header wall.

The invention will be more readily understood by way of example from the following description of a cooling system for a strip mill, reference being made to the accompanying drawing in which:

FIGURE 1 diagrammatically indicates a header and one of the delivery pipes of that header,

FIGURE 2 is an axial section of one of the delivery pipes, and

FIGURE 3 is an axial section of a modification.

FIGURE 1 illustrates several in line headers 12, 12', each of which is connected to a supply of water under pressure through a valve. Each header extends over the entire width of the strip path and is mounted with its axis horizontal and transversely disposed with respect to the strip path by means not shown. One end of the header is connected to a Water supply pipe which has a valve controlling the supply flow rate. A series of delivery pipes 13 is connected to the header at intervals along the length of the header. As shown, each pipe 13 is arranged vertically and on the vertical diameter through the header 12; each pipe terminates with its upper end above the horizontal diameter of the header.

As shown in FIGURE 2, each delivery pipe 13 is formed with a cylindrical outer wall 14, integral with a restriction 15- formed at the upper end of the pipe, when arranged in the header as shown in FIGURE 1. Following the restriction 15, there is a short dispersion zone 16- leading to streamlining means 17 which extend over the larger part of the length of the pipe 13. In the arrangement shown, the streamlining means 17 consist of a group of tubes, each having a diameter small compared with that of the pipe 13 and each arranged with its axis parallel to the axis of the pipe. However, other forms of streamlining means may be provided, such as a series of fins. Following the streamlining means 17 and arranged at the exit end of the pipe 13 is a convergent nozzle 18, in which the water passing through the individual passages of the streamlining means is collected, and which discharges the water from the pipe in a slightly convergent stream.

The header 12 is arranged so that the lower extremities of the pipes 13 are at such a distance above strip to be cooled that the jet remains unbroken during its fall and before it strikes the strip. Thus, the nozzles 18 may be arranged 5 feet above the mean path of the strip, when the flow will be laminar, provided that the flow rate is 5 gallons per minute or less and provided the diameter of the jet near the strip is not more than 0.3 inch. It will be appreciated that these values are those for true laminar flow, where the Reynolds number does not exceed 2,000. Flow resembling laminar flow and effective for cooling the strip efficiently may be obtained with values greater than those given.

In an example, each pipe 13 may be of 1 inch diameter and of 6 inches in length. The streamlining section 17 may comprise tubes of inch internal diameter and 4 inches in length. The exit diameter of the nozzle 18 may be inch.

In the modification of FIGURE 3, the header is again shown at 12 and one of the series of delivery pipes at 13. In this case, the delivery pipe 13 passes upwards through the top wall 12A of the header 12 and terminates in an open end a short distance above that wall. The upwardly protruding portion of pipe 13 is enclosed within a hemispherical dome 20 bolted to the wall 12A and spaced away from the upper extremity of the pipe. A number of holes 21, for example four, are formed in the wall 12A and these holes form restrictions through which water may pass from the header 12 to the interior of the dome 20' and thence to the pipe 13, without causing undue pressure drop in the header. The pipe 13 contains, as before, a streamlining section shown as constituted by small diameter tubes 17, and the streamlining section is followed by a collecting zone 22 preceding a convergent section 23. The turbulence generated by the passage through the holes 21 is smoothed during the passage of the water in the interior dome 20, as well as during passage through the streamlining section.

In an example each of the four holes 21 is diameter, equispaced on a 2 /2 diameter circle. The header 12 is 4 x 4 hollow section, while the streamlining section is again 4" long and formed by tubes of A bore. The exit diameter of the pipe 13 is Ms.

Preferably the dome 20 is formed with a dimple at its top as seen from outside the dome. The dimple extends inwardly to just beloW the level of the top of the pipe 13. This formation of the dome promotes smooth flow into the pipe.

In accordance with the provisions of the patent statutes, I have explained the principle and operation of my invention and have illustrated and described what I consider to represent the best embodiment thereof. However, I desire to have it understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A distributor for distributing cooling liquid, comprising:

a header tank arranged to receive cooling liquid under pressure;

a plurality of delivery pipes supported by said header tank with one of each pipe located below the tank and the other end of each pipe positioned above the tank;

means for promoting streamline flow in each delivery a plurality of cover members mounted on a wall of the header tank and each defining a chamber above the header tank into which the upper end of at least one of said delivery pipes extends, and with a plurality of restricted passages through said wall interconnecting the header tank with the chamber.

2. A distributor for distributing cooling liquid according to claim 1 wherein said delivery pipes extend through the header tank.

3. A distributor for distributing cooling liquid according to claim 1 wherein the said means for promoting streamline flow comprises a group of tubes or fins whose longitudinal axes are parallel to the associated said pipe.

4. A distributor for distributing cooling liquid according to claim 1 wherein the fluid volume of the chambers is considerably smaller than the fluid volume of the header.

5. A distributor for distributing cooling liquid according to claim 1 wherein the chamber is dome shaped.

6. A distributor for distributing cooling liquid according to claim 5 wherein the inside surface of the dome shaped chamber extends inwardly toward the top of a said delivery pipe to direct coolant thereto.

References Cited UNITED STATES PATENTS 2,408,588 10/1946 Watts 239-5535 3,263,933 8/1966 Porwancher et al. 239-533 X 3,268,176 8/1966 OBrien et al 239553.5

ROBERT A. OLEARY, Primary Examiner.

THEAPHIL W. STREULE, IR., Assistant Examiner.

U.S. C1. X.R. 239553.3, 552

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,420,447 January 7, 1969 David Robert Howard It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 35, after "one insert end Signed and sealed this 24th day of March 1970.

(SEAL);

Attest:

I WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attestin g Officer 

